What is “proprioceptive derivation” (pd)?

Much interest is focused on maintaining or restoring the abilities and health of the human body, but little interest is directed at the best use of the body for providing health care.

“Proprioception” (from Latin: self-perception) is self-awareness of the positions/movements within our own body.

It is the instinctive logical response of our body to maintaining balance in open space.
This inborn feeling is common to all human beings.

What exactly is this inborn wisdom of the body and how do we discover it?

First of all, before being professionals we are first and foremost human beings, and we all share some commonality within us: we are all under the influence of gravity – our common earth condition – and the 3 basic optimal postures of our body are lying down, sitting, standing/walking. For example, when standing on our 2 feet the most natural position is to be upright, as it is how we are able to make the least effort against gravity! It is inborn.

Now, if you want to do a precise work, how would you position yourself, and specially if it is to be for long hours, for the rest of your life? For example: threading a fine needle. How would you do it?

You would first try to find a natural and comfortable position, balanced, and without stress, by self-awareness of the positions/movements within your own body.

The “derivation” of our gesture/position comes from the inborn reaction (feedback) to what our body feels by searching spontaneously for its optimal balance with the least effort.

The full process involves both “proprioception” and “derivation” to become “proprioceptive derivation” (pd).

What is the purpose of pd in professional life?

Let us play the role of becoming a new “pd operator”, self aware of your body balance. For the sake of the experience, please forget for a few minutes all your past habits, without the preconception that adaptation is required to the products/equipment.

Forget the way you have been taught to treat your patients (often with your trunk bent and twisted over your patients, with your arm lifted) — experiencing a physical challenge with discomfort and tension.

In short, what do you want as a human being before jumping into the mouth of your patients? Surely, to be at ease, to be relaxed and in full balanced control, but how do you come to that state?

Imagine that you need to treat the first right upper molar, where/how would you like to be? You will find yourself in this position: in an upright state, your head balanced, with your operating finger in the middle of your chest at heart level. Why? Because it is here that you see best and therefore here is where you will control best your finger.

How to find your own pd sense?
To continue our discovery, we follow a few basic “pd exercises” – ideally with closed or masked eyes to concentrate (= enhancing the self-awareness of one’s body) – to determine the perfect condition of body balance with similar questions on how to feel/experience the “pd sense” by finding the optimal angulation position of the hand, fingers, forearm and wrist, the elbows lift, the minimum tilt of the head, the best visual point, the seat height, etc.

When these exercises are done, you will use your body best (not distracted by stressful and painful imbalance) with minimum tension and maximum finger control, in such a way that your efficiency and accuracy will increase your productivity).

How to remember which is Z,Y and X: DERIVE IT!
Stand in an open space and close your eyes.

Become aware that there are basically 3 axes in the space:
“up and down”
“forward and backward”
“right and left”.

Proprioceptively-based sense of order of direction of the 3 axes: If you have to put these axes in order, which feels to you like it comes first? i.e. which is the most basic, or primary? Most people say that “up and down” comes first.

The “up and down” axis is Z. Perhaps we have this feeling because the first thing we have to do as human beings, living with gravity, is counteract the down force of gravity.

Which comes second? Most people say that “front and back” comes second, and is more basic than left and right.

Proprioceptively-based ± (plus or minus) of the 3 axis X,Y,Z relative to the human body

Direction on axis: + and – denote 2 directions on each axis.
Plus and minus (±) are determined using our proprioceptive sense. Most people have the same sense of which is “+” and which is “ – ” .

The superior and inferior directions in the Z axis are denoted by plus and minus. Which direction feels like “plus”? Most people feel that the superior direction is “plus”, and the inferior direction is “minus” in Z axis.

In the Y axis, most people feel that the anterior direction is “plus” and the posterior direction is “minus”.

In the X axis, most people feel that right is “plus” and left “minus”.

“pd” exercises 3 and 4

3. Self-awareness of tension-free ELBOW lift:

Stand in an open space and close your eyes.
Assume your preferred body posture and head balance, and relax:
verify that arms and shoulders are hanging loosely.
Take a deep breath, exhale, relax.
Slowly lift your operating hand to the level at which you can best thread a needle, for example.
Maintain this hand position for the rest of this exercise.

Move your elbow forward (Y+) from the loosely hanging position until you begin to feel stress. Repeat several times. Measure the range.

Move your elbow laterally (X+) from the loosely hanging position until you begin to feel stress. Repeat several times. Measure the range

This is your “zero range” of elbow movement (a few centimetres only)

4. Self-awareness of tension-free HEAD tilt:

Stand in open space and close your eyes.
Assume your preferred body posture with head balanced.
Take a deep breath, exhale, and relax.

– Become aware of your preferred range of lateral head tilt by bending your head from side to side.
Repeat several times. Verify that you prefer to not tilt your head to the side any more than X cm.

– Become aware of your preferred range of forward head tilt by bending your head forward and backward. Repeat several times. Verify that you prefer to not tilt your head forward any more than Y cm.

“pd” exercises 5 and 6

To measure the best visual distance:
Stand in open space.
Close your eyes.
Assume your preferred body posture with head balanced.
Take a deep breath, exhale and relax.

Slowly lift your operating hand to the level at which you can best thread a needle, for example.

Freeze your head and finger in this position.
Open your eyes.
Can you see clearly your operating finger tip?
Place a dot by the outer canthus of your eye.
Maintaining your preferred body posture and head balance, touch the “finger point” to the tip of your nose.

Slowly move your finger tip away from your nose and identify the distance at which you can see the fingerprints best. After measuring the optimum distance in Y direction of your operating index from sternum, you will get your “0 point”.

This is your “focus point”. This is your “0 point”

6. Seat height instruction

Sitting on a stool, with no back contact, assume your preferred upper body posture with balanced head.

Derive your preferred seat height by moving the stool up and down or adding or removing a few planks.

Seat height

After seating yourself at your preferred seat height, we measure the distance from the floor to your 0 point at your operating index for optimal control.

0 point of the operator (finger tip index) coincides with the 0 point of the patient (inter incisal point between 11 and 21).

These are the basic exercises for all human beings. Pd dentists will have to go further in relation to patients, equipment and instruments.

The secret is to be aware of your pd balance all the time until it becomes part of you naturally.

These conclusions were based on proprioceptive derivation. No one taught you!

The 0 point and pd for optimum use of the body

A human-centered approach gives us the key to a universal method which is revolutionary in many ways.

Developing self-awareness of the body enhances the manual skill, allowing the easiest movements with minimum tension and maximum precision in direct and indirect views*

Complex tasks – like those involved in dentistry – can be done in best body conditions with the greatest accuracy and precision, avoiding thereby muscular-skeletal disorders.

*There is a systematized way to handle a pd mirror for the best associated views

Optimal body balanced posture and position.

Pd is the global principle for optimum use of operators’ fingers with associated views of operating points from which working posture & position of the operators and the whole dental clinic can be derived.

“Optimal posture and position”

pd unit in the ADCERRA clinic

– Only pd units built according to “human-centered standards” (called also “global standards”) common to all human beings with a flat horizontal support rising up and down – instead of a tilting back rest – will be beneficial to dentists all around the world, by allowing them to maintain natural upright balanced postures in free open space, which correspond to the real need of the operator’s body derived by self-awareness.

The natural posture of the dentist (seated behind the head of the patient at full rest horizontal position) and easy free movements automatically enhance maximum finger control.

– Method of treatment by pd dentists. They work in free upright position with their head balanced and with loosely hanging elbows.

2. Patients are lying horizontally on fixed human support (no tilting backrest).
3. Open space (machinery inside the unit).
4. Total concentration of the operator in harmony with the assistant for the safest care.
The pd dentists operate on a pd unit which provides them with the easiest way and the optimum conditions to maintain high quality of care with the highest control of fingers for the benefit of the patients.

- Optimized pd treatment area with a pd unit and cabinet:

the area is an open space (6 m2) where the pd unit is the centre piece (the machinery is hidden inside the unit) allowing free movements of the operator and featuring:

The benefits
• for patient: safer and better care,
• for care providers: least body tension and better skeletal-muscular health, thanks to a working posture that can be maintained for a long time without fatigue. This means that a dentist can do his job in a healthy way over a normal working lifetime.

This Global Concept provides the easiest way and the optimum conditions to maintain high quality care with best control of fingers for the benefit of patients all around the world.